`aura --help` and `aura -h` are a newcomer's reflex first command, but
today they hit the unknown-subcommand error path: exit 2, empty stdout,
one-line `aura: usage: aura run` on stderr. For a C22 "newcomer sees a
populated trace" milestone the conventional help affordance returning
the error path is a first-contact friction.
This compile-clean RED pins the desired success-path contract: `--help`
and `-h` print non-empty usage to stdout and exit 0, and the usage names
the `run` subcommand. A negative-preservation assertion keeps an unknown
subcommand (`frobnicate`) on the exit-2 error path so the fix cannot
regress bad-args handling. Asserts structural facts only (exit code,
non-empty stdout, mentions `run`), not exact help prose.
refs #20
Brummel
07ba20a991